Work has continued in the past year to improve artificial breeding methods for the chimpanzee. Methods for superovulation have been developed using human menopausal gonadotropins. The success rate of A.I. has been raised to over 80% for a single insemination when specific parameters of the inseminated cycle have been met. At this time such identification is by observation of the spontaneous cycle, however, future work will be directed to iatrogenic initiation of such highly fertile cycles. The alteration in fertility is likely associated with endometrial development and alteration of implantation rate. As a consequence of a restriction in breeding of the common chimpanzee, we are increasing efforts directed to creation and cryobanking of embryos created using In vitro fertilization and ICSI. To date embryos have been banked from the common chimpanzee (P. Troglodytes) and the sooty mangabey (c. Atys). In addition, we are studying the potential effects of fish an tifreeze proteins as cryoprotectants for semen storage.